Threats and abuse were hurled at a Liverpool Crown Court judge after he sentenced a youth to detention.
Two teenagers in the public gallery began kicking the glass panel behind the dock and started shouting foul abuse at Judge David Swift.
As they got to the courtroom door, where they were being ushered out, they continued their verbal onslaught threatening to attack both the judge and his wife.
Judge Swift ordered that they should be arrested but they fled from the building - but not before one hurled a fire extinguisher at a window on the fifth floor landing smashing it.
The other one was caught outside the Derby Square building and brought back to court. After a couple of hours in the cells the 16-year-old schoollboy was brought before the judge in handcuffs.
Asked if he had anything to say about his behaviour, the boy, who cannot be identified for legal reasons, shook his head. Judge Swift ruled that his earlier behaviour was a contempt of court.
The case was put back for half an hour while barristers investigated the judge's powers and Jonathan Clarke, defending, then said that the judge had no power to impose a custodial or community sentence so the only effective punishment was a fine.
Judge Swift, who had a tape recording of the outburst played to the lad, asked him, "Are you the slightest bit sorry for that outburst?" to which he replied, " a bit like."
The judge imposed a £150 fine which he ruled the boy's parents must pay within 28 days.
The case he and his companion had come to observe involved 18-year-old Eric Bromilow, of Ashvile Road, Poulton, Wallasey, and Thomas McNicholas, 23, of Ilcrest Court, Breck Road, Wallasey.
Bromilow, who admitted inflicting grievous bodily harm, was sentenced to 10 months detention and McNicholas, who admitted assault causing actual bodily harm, was sentenced to five months imprisonmenrt suspended for two years and placed under supervision for two years.
Michael Bagley, prosecuting, said that on March 15 last year a 17-year-old youth went for a drink with friends and his father, who was with his partner, in Birkenhead.
The friends included Bromilow and McNicholas and during the evening McNicholas started making remarks about his father's partner . The boy told his dad but the couple were apparently already aware of the remarks and she was upset and they left.
McNicholas accused the boy of being 'a grass' and was determined to fight. The boy did not want to get involved and ignored his attempts to get him to fight and eventually left the pub.
But as he was walking towards Hamilton Square McNicholas pushed him over some small railings and began punching him. Bromilow had also followed him and when the victim got to his feet Bromilow punched him on the jaw causing a double fracture.
Keith Sutton, defending, said that Bromilow had been out of trouble for nine months and realised he needs to grow up. His partner gave birth to his child in December, he added.
Defence barrister Gareth Bellis said that McNicholas had acted out of character while drunk.